| abstract |
An additive composition having Viscosity Index improving, dispersant and anti-oxidant properties is prepared by graft polymerization on the polymer of 15 to 80 mole percent of ethylene, from 20 to 85 mole percent of C₃ - C₁₀ alpha-monoolefin, and from 0 to 15 mole percent of non-conjugated diene or triene having an average molecular weight ranging from labout 5000 to 500,000. This polymer is reacted with at least one olefinic carboxylic acid acylating agent to form one or more acylating reaction intermediates having a carboxylic acid acylating function and the additive is formed by reacting said acylating function and the additive is formed by reacting said reaction intermediate with an amino-aromatic polyamine compound selected from an N-arylphenylenediamine, an aminothiazole, an aminocarbazole, an aminoindole, and aminopyrrole, an amino-indazolinone, an aminomercaptotriazole, and an aminoperimidine. |